Method and apparatus for making well casings



Sept. 6, 1938. E. F DOOLEY METHOD AND APPARATUS FOR MAKING WELL CASINGSFiled Jan. 13, 1956 2 Sheets-Sheet l Sept. 6, 1938. E. F. DOOLEY METHODAND APPARATUS FOR MAKING WELL CASINGS Filed Jan. 15, 1936 2 Sheets-Sheet2 lii:

'EDARDEDOOLEY Patented Sept. 6, 1938 UNITED STATES PATENT OFFICE METHODAND APPARATUS FOR MAKING WELL CASINGS This invention relates to a methodand apparatus for making well casings.

Briefly, the invention contemplates a perforated well casing of the typesuggested that is characterized by the power to resist such degenerativenatural influences as rust and electrolysis.

Also, a perforated casing embodying the invention will be found to bemarked by the presence of a plurality of longitudinally andcircumferentially extending members which serve not only to strengthenand reinforce the casing but which provide a gating in which there is aquick and easy flow of the metal from which the casing is molded and inthis way, the casting operation is facilitated and an improved productis achieved.

By way of further brief preliminary allusion to the longitudinally andcircumferentially extending members which strengthen the casing, itmight be pointed out that the arrangement of the same enables the casingto resist buckling, when being driven into place in deep wells, and towithstand external pressures created by caveins and by the surroundingformation.

In speaking briefly of the manner in which the longitudinally andcircumferentially extending strengthening members assist in the castingoperation, reference is made to the fact that the same 39 provide forthe expeditious fllling of the mold and, while fllling, to create aslittle disturbance 88 possible in the metal.

Another important aspect of the invention has to do with the method andstructure by which 35 the casing is cast. For example, it is requiredthat each cheek of the flask, with a slotted ring pattern therein andrammed up, be transferred from the mold board to the drag or to apreceding cheek before the slotted ring pattern is drawn 40 so that whenthis ring is drawn, the core within the cheek being handled will besupported against collapse by the molding sand immediately below.

On the other hand, if the slotted ring pattern were drawn from the sandprior to placing the cheek in final molding position, an attempt to movethe cheek to such position would result in the collapse of the corebecause the core would be left without an adequate supporting connec- 50tion with the surrounding molding sand and in fact without a realsupportof any kind.

Other objects and advantages will be apparent during the course of thefollowing description.

In the accompanying drawings, forming a part 55 of this application andin which l ke u era s a e employed to designate like parts throughoutthe same,

Figure 1 is a side elevation of a perforated well casing embodying theinvention, a part of the casing being broken away, 5

Figure 2 is a horizontal sectional view taken on line 2-2 of Figure 1,

Figure 3 is an enlarged detail view, in side elevation, and taken online 1-3 of Figure 2,

Figure 4 is a fragmentary perspective of a cope 10 ring pattern which,of course, is placed at the top of the molding flask and which providesfor the formation of an attaching extension at one end of the casing,

Figure 5 is a fragmentary perspective of a 15 slotted ring patternembodied in the invention,

Figure 6 is a fragmentary perspective of a bottom ring pattern which, ofcourse, is mounted in the drag or nowel of the. flask,

Figure 7 is a vertical sectional view through the 20 drag of the flask,rammed up and ready to be rolled over,

Figure 8-isa vertical sectional view of the dra after being rolled over,the view illustrating the removal of the lower pattern ring, 25

Figure 9 is a vertical sectional view througha check of the flask rammedup and ready to be placed in molding position on the drag or aprevious'ly placed check, a portion of the core of the mold being brokenaway to better illustrate the associated pattern ring,

Figure 10 is a vertical sectional view disclosing a cheek of the flaskrammed up and mounted on the drag, the slotted pattern ring being shownin full and dotted line positions to illustrate that it is only afterthe cheek of the flask has been placed in flnal molding position, eitheron the drag or a previously placed flask, that the slotted pattern ringis drawn,

Figure 11 is a vertical sectional view through a partly built up flaskwith the slotted ring pattern partly drawn from the previously placeduppermost cheek,

Figure 12 is a vertical sectional view through the rammed up cope of theflask,

Figure 13 is a fragmentary vertical sectional view through the assembledflask ready for the metal to be poured,

Figure 14 is a horizontal sectional view taken on line "-44 of Figure13. I 50 In the drawings, the numeral 20 generally designates a hollowcylindrical casing especially adapted for use in water wells and which,as is important to observe, is cast from gray iron.

In certain parts of the country. due to the min- 5 eral content of wellwater and to the nature of the formations encountered in wells, theprovision of a durable and efficient perforated casing for wells is amatter of considerable interest and concern. Perforated galvanized steelcasings have been found to be highly susceptible to the deleteriousefi'ects of rust and electrolysis. This is due in a large measure to therefined nature of the metal. Cement casings have a tendency to crumbleand collapse under the pressure of cavy and other subterraneanformations. However, it has been found that by casting the perforatedcasing from gray iron the same is better enabled to withstand thedegenerative effects of rust and electrolysis and at the same time whenthe casing is cast from iron after the fashion disclosed herein, it willnot buckle when being driven into place in deep wells or collapse undersuch forces as cave-ins and the pressure of the surrounding formation.

In Figure 1, the perforated casing is shown to consist of a lower endband 24, a plurality of longitudinally spaced, intermediate,circumferentially extending bands 28 and an upper band 28. Clearly, theupper band 28 is of an external diameter to fit snugly within the lowerend band 24 of a meeting section or in some other part of the fluidconduit of a well.

Of course, the bands 24, 28 and'28 are all positioned about a commonaxis and as clearly illustrated in Figures 1, 2 and 3, such bands areintersected and joined by a plurality of circumferentially spaced,longitudinally extending major strips or members 38. In carrying out theinvention, the portions of metal between the circumferentially extendingbands and the longitudinally extending strips 38 are longitudinallyslotted as indicated at 34. The slots define circumferentially andlongitudinally spaced groups of longitudinally extending minor strips 36between the major strips 38. In other words, the circumferentiallyextending bands 24, 26 and 28 cooperate with the longitudinallyextending strips in the formation of a rigid and stout framework betweenwhich the groups of spaced strips 36 are located for the admission offluid to the casing.

As previously suggested, the casing 20 has the power to resistbucklingwhile being installed and at the same time is enabled to resist externalpressures. These attributes are accounted for by the presence andarrangement of the annuli 24, 28 and 28 and the longitudinally extendingmembers 38, all of these parts being substantially stouter than theminor strips 36 that are surrounded by these major members.

By reference to Figure '2, it will be seen that the minor longitudinallyextending strips 36 are increased in cross-section radially outward toprovide maximum strength, in combination with generously proportionedopenings for fluid while at the same time facilitating manufacture.

Figure 7 discloses that in manufacture, the mold board 48 of the drag ornowel 42 is formed in the upper surface thereof with an annular groovefor the reception of a ring pattern 44. It is believed to be clear thatthe ring pattern 44 corresponds to the lower end band 24 of the casing20 and that after the drag, with the ring pattern 44 positioned therein,has been rammed up, it is rolled over so as to occupy the position shownin Figure 8. With the drag thus rolled over, the ring pattern 44, whichwill be found to project slightly above the sand, is drawn so as toprepare forthe final placing of the first check of the flask.

In Figure 5, it is illustrated that the mold board 58 for each cheekflask 52 is formed with an annular concentric groove 54 receiving theotherwise free terminal portion of a slotted ring pattern 58. Aftermounting the ring, the cheek is rammed up. With the cheek 52 thus rammedup, and with the ring pattern 56 still in place, the check istransferred to position on the drag. That is to say, the rammed up cheek52 with the core therein, is transferred from the mold board,

and without being rolled over, to the drag. During this transfer of therammed up cheek to final molding position, the core of the mold iscaused to remain in place through the continued presence of the patternring 58.

Thus, it is only after the cheek has been placed in position on the dragthat the pattern ring 58 is drawn. In this way, the core.of the mold ismaintained intact while being transferred from the mold board to thedrag.

As illustrated in Figure 5, the slotted ring pattern 58 consists of anunbroken annulus having an axial dimension which may approximate that ofeach of the intermediate circumferential bands 26. From this annulus,major and minor fingers 58 and 60, respectively, depend, the fingers 58corresponding to the longitudinally extending members 38 while the minorfingers 80 correspond to the minor strips.35.

In other words, the slotted ring pattern 58 is in the nature of acontinuous annular body having groups of longitudinally extending slotsopening out through the lower end thereof and defining the relativelybroad fingers 58 and the intervening groups of spaced minor fingers 88.

It is clearly shown in Figure 9 that the otherwise free lower terminalportions of the fingers 58 and 60 are seated in the groove 54 ,of themold board 50. In this way, the ring pattern is held concentric oragainst distortion and in properly centered position.

With the first cheek thus positioned on the drag, and the ring patternremoved, as many additional cheeks may be added as are necessary toprovide for the casting of a casing of the required length. For example,if each ring pattern is six inches long, it is a simple matter toprovide six cheeks for the casting of a casing three feet long, dueregard being had, of course, for the end bands 24 and 28.

Of course, in making up the mold, the ring pattern 56 is arranged withthe fingers 58 and 68 in the line of the corresponding cavities below.

The ring pattern 56 has an axial dimension somewhat greater than that ofthe surrounding cheek so that the top of said ring pattern may be flushwith the top of the cheek while the lower portion of the patternprojects below the cheek and into the annular cavity immediately below.

It is important to observe that, with the addition of each cheek, it isrequired that the slotted ring pattern be allowed to remain thereinuntil the cheek is transferred from the mold board to a preceding cheek.With the cheek thus placed in final molding position, the slottedpattern ring may be drawn because the core of the mold will then besupported against collapse by the molding sand immediately below or byother means employed for this purpose. That is to say, each cheek, afterbeing rammed up, and with the ring pattern therein, is transferred fromthe mold board to final molding position and during this transfer, thecore of the mold is temporarily amasvo supported against collapse by thesurroundins ring pattern.

After therequired number of cheeks have been placed in final moldingposition, the flask is coped, attention in this connection being invitedto Figures 12 and 13. In Figure 12, it is illus trated that the moldboard 10 of the cope is formed with an annular groove I2 adapted for.the reception of one edge portion ofthe ring pattern I4. Of course, thepattern ring 14 corresponds to the attaching portion 28 of the casing.

with the pattern ring 14 thus in place, the cope I8 is rammed up and isthen rolled over for the removal of the pattern ring. This is followedby the mounting of the cope on the uppermost cheek so as to complete themolding cavity for the perforated casing.

with the mold thus set up as illustrated in Figure 13, it is gated forthe admission of the molten metal and in this connection it is importantto observe that the cavities left in the sand by the depending fingers58 and by the unbroken annulus of the ring pattern 56 provide for thequick and easy flow of metal to and into the various other moldingcavities. That is to say, the cavities defined by the fingers 58 and theunbroken annuli at the ends of the slotted ring patterns 86 extendthroughout the length and breadth of the completed casting at more orless uniformly spaced points so that the presence of the bands 24, 26and 28 and the longitudinal members 80 in the completed article not onlystrengthen and reinforce the article itself but at the same time providefor ready gating, with the result that an improved article is achievedand the percentage -of rejections is reduced.

Figure 13 illustrates my method of pouring the mold which provides forgating at the joint of the first and second cheeks, on the inside, ofcourse, although the mold could be poured from the outside by the use ofa larger flask to allow for the gate sticks and the runner.

The runner which is designated by the numeral 250 is of annular form andis located at the point of connection of the first and second cheeks. I

Also, the gates 252 are shown to radiate from the runner 250 and connectwith the molding cavity at the points originally occupied by theunbroken annuli of the molding rings and in line with the members 88. Inthis way, I provide for the flow of metal into the cavity at the pointswhere its rapid and uniform distribution is assured. The gate sticks orsprues 260 extend downward from the top of the cope to the runner and,obviously, serve for the conduct of the molten metal from the ladies orthe like to the runner.

From Figures 1 and 3, it will be seen that although the spacedcircumferentially extending reinforcing bands 24, 28 and 28 have agreater wall thickness than the longitudinally extending strips 30 and36, the outer surfaces of such bands are flush with the correspondingsurfaces of the strips to avoid protruding ribs or other projections onthe exterior of the casing which might interfere with the introductionof the casing into a well. That is to say, the reinforcing bands areflush with the outer surfaces of the strips 30 and 88, to provide acasing having a smooth external surface, but project radially inwardbeyond the inner surfaces of the strips to give the required strength.

From the foregoing, it will beseen that the manufacture of the wellcasing from cast iron provides the power to resist the deleteriousinfluences encountered in wells in various parts of the country, whilethe presence of the bands 24, 28 and 28 and the union of these bandswith the longitudinally extending members, 30 provides the strengthnecessary to withstand buckling and external pressures and at the sametime, such members 24, 28, 28 and 80 lookto expeditious. simplified andless costly manufacture through providing a place for the gate.

Having thus described the invention, what is claimed is:

1. In a pattern for casting slotted cylindrical well casings withcircumferentially spaced, longi-' tudinally extending members and withcircumferentially extending annular bands intersecting and joining thelongitudinal members, an unbroken annulus which when rammed up in asection of a flask forms a molding cavity for the formation of acircumferentially extending strengthening band, said pattern also beingprovided with a plurality of longitudinally extending portions dependingfrom the annulus and spaced about the circumference of the pattern todefine circumferentially spaced, longitudinally extending places for thegate during casting and to give to the casing a plurality oflongitudinally extending members, the pattern between said dependingiongitudinally extending portions being provided with a plurality ofslots spaced apart less than the widths of the individual dependinglongitudinally extending portions to define fingers looking to slots inthe casing.

2. In a structure for casting slotted well casings in molding sand, aring pattern having at its upper end an unbroken annulus and a pluralityof slots extending longitudinally of the pattern from the unbrokenannulus and opening out through the lower end thereof to define anannular series of fingers, a mold board having an annular groovereceiving the lower terminal portions of said fingers to hold the ringpattern concentric and in place and to cause the lower terminal portionsof the fingers to project below the molding sand, and a cheek flaskreceiving the pattern and having the upper edge thereof flush with thetop of the pattern.

3. In a pattern for use in casting slotted cylindrical well casings withcircumferentially spaced, longitudinally extending members and withcircumferentially extending, annular strengthening bands intersectingand joining the longitudinal members, an unbroken annulus which whenrammed up in a section of a flask forms an annular molding cavity forthe formation of a circumferentially extending strengthening band, saidpattern also being provided with a plurality of longitudinally extendingportions depending from the annulus and spaced about the circumferenceof the pattern to define circumferentially spaced, longitudinallyextending molding cavities communicating with said annular moldingcavity for defining the circumferentially spaced, longitudinallyextending members of the well casing.

4. The herein described method of casting from metal a cylindricalcasing having a series of circumferentially spaced longitudinal slotsinterrupted by longitudinally spaced circumferential bands, whichcomprises providing a plurality of mold sections, forming mold cavitiesin the mold sections by means of removable patterns, said mold cavitieseach comprising an annular channel opening to one edge of the moldsection and a-plurality of spaced longitudinally extending channelsconnecting the annular channel with the opposite edge of the moldsection, assembling said mold sectionswith the annular channel of themold cavity of each section in alignment and direct communication withthe ends of the spaced longitudinal channels of the mold cavity of thenext adjacent section, and pouring molten metal into the mold cavityformed by the assembled mold sections.

5. The herein described method of casting from metal a cylindricalcasing having a series of circumferentially spaced longitudinal slotsinterrupted by longitudinally spaced circumferential bands, whichcomprises providing a plurality of mold sections, forming mold cavitiesin the mold sections by means of removable patterns,

the mold cavity in one of said sections comprising an annular channelopening to one edge of the mold section and the mold cavity in each ofthe other sections comprising an annular channel opening to one edge ofthe mold section and a plurality of spaced longitudinally extendingchannels connecting the annular channel with the opposite edge of themold section, assembling said mold sections with the annular channel ofthe mold cavity of each section in alignment and directcommunication'with the ends of the spaced longitudinal channels of themold cavity of the next adjacent section, and pouring molten metal intothe mold cavity formed by the assembled mold sections.

6. The herein described method of casting from metal a cylindrical wellcasing having a series of circumferentially spaced longitudinal slotsinterrupted by longitudinally spaced circumferential bands, whichcomprises providing a plurality of mold sections, forming mold cavitiesin the mold sections by means of removable patterns, said mold cavitieseach comprising an annular channel opening to one edge of the moldsection and a plurality 01' spaced longitudinally extending channelsconnecting the annular channel with the opposite edge of the moldsection, assembling said mold sections with the annular channel of themold cavityof each section in alignment and direct communication withthe ends of the spaced longitudinal channels of the mold cavity of thenext adjacent section, the annular channels having a greater thicknessthan the longitudinally extending channels and projecting radiallyinward beyond the longitudinally extending channels, and pouring moltenmetal into the mold cavity formed by the assembled sections.

'1. The herein described method of casting from metal a cylindrical wellcasing having a series of circumferentially spaced longitudinal slotsinterrupted by longitudinally spaced cir- .cumferential bands, whichcomprises providing a plurality of mold sections, forming mold cavitiesin the mold sections by means of removable patterns, said mold cavitieseach comprising an annular channel opening to one edge of the moldsection and a plurality of spaced longitudinally extending channelsconnecting the annular channel with the opposite edge of the moldsection, assembling said mold sections with the annular channel of themold cavity of each section in alignment and direct communication withthe ends of the spaced longitudinal channels of the mold cavity of thenext adjacent section, the annular channels having a greater thicknessthan the longitudinally extending channels, and the longitudinalchannels at spaced points about the circumference of each mold sectionbeing of greater width than the intervening longitudinal channels, saidwide longitudinal channels of the several mold sections being arrangedin longi tudinal alignment, gating the mold at the annular channel ofone of the mold sections in line with one of the wide longitudinalchannels thereof, and pouring molten metal into the mold cavity formedby the assembled mold sections.

EDWARD F. DOOLEY.

